Pump casing



' May 2, 1967 E. EGGER 3,316,848

PUMP cAsING Filed July e, 1965 5 Sheets-Sheet 1 May 2, 1967 E. EGGER 3,316,848

PUMP CASING F'iled July 6, 1965 5 Sheets-$11661; 2

ZO T\ l 44er 36 INVENTOR.

Ef EGGER May 2, 1967 PUMP CAS ING 5 Sheets-Sheet 5 Filed July 6, 1965 JNVENTOR. 7V/cc Esc-fe May 2, 1967 E. EGGER 3,316,848

PUMP CASING Filed July 6, 1965 5 SheetSSheet 4 JNVENTOR. [v1/Lf GGG? May 2, 1967 E. EGGER 3,316,848

PUMP CSING Filed July 6, 1965 5 SheeCS-Shee 5 N26 Ti q S.

INVENTOR. f1/LE 66E/Q h/WW? Trop/V06 United States Patent O 3,316,848 PUMP CASING Emile Egger, Cressier, Neuchatel, Switzerland, assignor to Emile Egger & Co., AG., Cressier, Switzerland, a corporation of Switzerland Filed July 6, 1965, Ser. No. 469,781 Claims priority, application Switzerland, July 14, 1964,

9,223/64; Nov. 28, 1964, 15,376/ 64 21 Claims. (Cl. 10S-103) The invention relates to a pump casing which can be employed with a variety of types of pumps and more in particular to a standardized pump casing which can be employed with any one of a plurality of diilerent types of rotary impellers.

A variety of pumps having different types of rotary impellers and therefore diierent operating characteristics for pumping under a variety of operating conditions have been developed. Certain pumps have been conditioned to pump material having a relatively low viscosty such as water. Other pumps have been conditioned to handle mixtures of uids or materials of comparatively high viscosity and in certain cases with amounts of entrained gasses. In addition pumps have been provided which are capable of handling solids suspended in fluids, such as found in process industries or in the pumping of sewerage water.

In the pump industry it has been customary to construct a specially designed pump for each of the different operating environments. Because of the variety of different iluids and materials which must be pumped, it has become necessary in the pump industry to manufacture and stock a greatnumber of different types of pumps as well as spare parts for them. As a result, there is today practically no interchangeability of pump parts and thus large inventories of pumps and pump parts must be maintained. The failure to provide interchangeability in pump components persists even though many of the components of a plurality of different pumps are closely related in size and form. One of the reasons for this is that in spite of similarities in various pump components, it has been the practice of the pump industry to incorporate relatively slight constructional differences between related pumps in order to achieve eiiicient and satisfactory operation of each diderent type of pump.

The absence of interchangeability has continued up to the present time even though most of the different pump designs comprise an assembly of certain basic elements such as a rotary impeller, a pump casing in which the rotor is disposed, inlet and outlet openings for the casing, a rotary impeller, a casing cover and means for sealing the shaft of the impeller to the casing when the impeller is disposed therein. The lack of interchangeability of pump components can be an expensive drawback espe- "cia lly when it comes to the area of relatively large pumps of the type used in industry, public utilities or in connection with sewerage treatment equipment.

The lack of interchangeability is especially a problem with respect to the pump casing. The reason for this is that the pump casing is commonly the largest single element of a pump which necessarily must contain a comparatively intricate interior portion, an inlet opening, an outlet opening and an opening for receiving the impeller and the shaft upon which the impeller is mounted. In many instances the casing is formed by casting. Since in the past each different type of pump has included changes in the form of the interior of the pump casing, it has been necessary to supply patterns, molds and other casting equipment for producing each of the different casings, regardless of how small the diierences are. The same is true where the casing is machined, since each different casing can require different tooling and machining procedures even where relatively minor variations exist between different types of casings.

It is therefore one of the objects of the invention to provide a standardized pump casing which can be used with any one of a plurality of different types of rotary impellers.

It is another object of the invention to provide a standardized pump casing which can be used with a plurality of different types of rotary impellers which are disposed at a variety of relative positions Within the casing.

It is still another object of the invention to provide a standardized pump casing which can be used with rotary impellers having a variety of ow characteristics with respect to the interior of the casing.

It is an additional object of the invention to provide a standardized pump casing for a plurality of rotary impellers which require different inlet ow conditions.

It is a further object of the invention to provide standardized pump casings which can be used with a plurality of different pump casing covers wihch corresponds to a number of diiferent types of rotary impellers.

It is a further :object of the invention to provide standardized pump casing which can be used with a number of diierent supports for the impeller shaft seal which can vary for different rotary impellers.

In one embodiment of the invention the standardized pump casing is adapted to receive a rotary impeller which is one type of a plurality of diiierent types of rotary impellers. The pump casing includes a pair of wall portions disposed opposite and spaced apart from one another and an annular wall portion which connects together the pair of wall portions. One of the pairs of wall portions includes an opening for receiving the impeller and shaft. This Wall portion adjacent the opening therein is adapted to engage the pump casing cover which corresponds to the particular rotary impeller being used. The annular wall portion is provided with an outlet opening for the casing. The other Wall portion of the casing includes an inlet opening and is provided with means adjacent to the inlet opening and exposed to the interior of the casing for engaging an insert member for directing the ilow of fluid moving through the inlet opening toward the impeller. The means for engaging an insert member is adapted to engage any one of a plurality of insert memgbers, some of which include means for guiding the fluid for recirculation within the casing in additon to a cylndrical openmg. f

An advantage of the standardized pump casing of the invention is that it can be selectively assembled with any one type of a plurality of types of rotary impellers. Thus in order to obtain a Variety of pum-ps, it is merely necessary to provide different rotary impellers while using a single standardized pump casing,

In another embodiment of the invention the opening in the wall portion rfor receiving the impeller and shaft comprises a cylindrical bore which is adapted to engage the cover of the pump casing.

In still another embodiment of the invention the means adjacent to the inlet and exposed to the interior of the casing for engaging an insert member includes a recess formed in the casing and adapted to receive an insert member. An advantage of this arrangement is that any one of a plurality of different insert members can be readily installed in the recess in order to accommodate the particular rotary impeller selected for the casing.

In an additional embodiment of the invention the interior of the casing adjacent to the inlet opening is provided with a seat to mount the insert member in conjunction With the recess adjacent to the inlet opening.

It is a further object of the invention to provide the combination of a standardized Vpump casing with an insert member therein conditioned to correspond to the type of impeller which is to be installed in the casing.

Other objects and advantages will become apparent from the following, description taken in conjunction with the accompanying drawings in which:

FIG. 1 is a vertical section view of a pump having a radially directed centrifugal impeller and the standardized pump casing of the invention;

FIG. 2 is a vertical section view of a pump having another .form of a radially extending centrifugal impeller and a standardized pump casing;

FIG. 3 is a vertical section View of a pump having a recessed impeller and a standardized pump casing',

FIG. 4 is a vertical section View of a pump having a Combined radially and axially extending centrifugal irnpeller and a standardized pump casing;

FIG. 5 is a vertical section View of a pump having a propeller-type impeller and a standardized pump casing; and

FIG. 6 is a vertical section view of the standardized pump casing of the invention.

The standardized pump casing of the invention, as shown in FIG. 6, includes wall portion 21 which contains openings or bore 22. Opposite and spaced from wall portion 21 is wall portion 23. Annular wall portion 24 connects wall portions 21 and 23 and thereby forms chamber within the casing. As shown in the drawings, the section of wall portion 24 is substantially of a semi-circular form which facilitates recirculating flow moving outwardly and from wall 21, along annular wall portion 24 and toward wall portion 23. As shown in FIG. 6, the annular wall portion forms a portion of a toroid which extends about the pump chamber. The central axis of casing 20 is coextensive with the longitudinal axis of the shaft for the impeller which is to be disposed in the casing. In addition, the various portions of the casing, such as Wall portion 21 and 23 and annular wall portion 24 are symmetrically disposed with respect to the central axis.

Outlet opening or outlet 26 extends radially in a tangential mauner from chamber 25 of the casing. Flange 27 enables outlet 26 to be connected to the discharge line (not shown) to which the ow of the pump is to be delivered. Inlet opening or inlet 28 is connected to wall portion 23 and is in communication with chamber 25 of the casing.

As shown in FIG. 1, pump 29 is assembled with casing 20. The pump includes a radial-flow type of centrifugal impeller 30 which is mounted on shaft 31 and retained thereby nut 32. Shaft 31 extends through seal support 33 which contains packing 34 retained therein by gland nut 35. Seal support 33 is provided with shoulder 33a which positions the seal support with respect toA bore 22 of the casing. Flange 33h of the seal support limits the engagement of the support with respect to the bore. Attached to seal support 33 is housing 36 which surrounds shaft 31 and couples the pump to the housing of the electric motor or other power source which drives the pump.

Impeller 30 includes a plurality of radially extending enclosed passages 30a which direct the flow of Ifluid to- Ward t-he area of wall portion 24 which is adjacent to bore 22. As shown by the arrows in FIG. 1, the flow from the impeller follows the semi-circular section of annular wall portion 24 as the ow advances toward wall portion 21. Since it is desired to produce a recirculating flow condition within casing 20, as indicated by the flow lines in FIG. l, the casing is provided with insert member or insert 37. Insert 37 includes curved external surface 37a which faces toward the interior of casing 20 and is faired into the surface of wall portion 24. As a result, surface 37a can reverse the ow passing along wall portion 21 toward impeller 30. In this way the ow from the impeller is induced by insert 37 to recirculate within casing 20 in the form of a vortex.

Insert 37, which contains cylindrical opening 37b is provided with flange 37C which engages recess 38 within the casing. Opening 37b receives the ow from inlet 28 and directs it toward passages 30a of impeller 30. Insert 37 is provided with seal ring 39 which serves to seal the stationary insert 37 with respect to rotary irnpeller 30. In addition to recess 38, casing 20 is provided with recess or seat 42 for receiving the outer portion of insert 37 Thus as shown in FIG. l, insert 37 can be accurately positioned in casing 20- and thereby with respect to impeller 30 by means of recesses 38-42. Further as shown in FIG. 1, it can be seen that surface 37a of the recess, inconjunction with the wall portion 23, annular Wall portion 24, and wall portion 21, form a chamber 25 which is substantially circular in a radially extending cross-section taken along a plane which includes the axis of shaft 31. The vortex or recirculating flow can be maintained throughout chamber 25 since it has substantially constant cross-section. Cavity 40 behind the central portion of the reverse side of impeller 30 is vented to passage 30a by openings 30h. Impeller 30 is provided with seal ring 30C for separating and preventing iiow between cavity 40 and cavity 41 behind the outer portion Vof impeller 30.

amplifier as shown in FIG. l `are approximately one-fourth of the axial width of chamber 25 within casing 20. Thus, the impeller being axially offset or eccent'rically positioned with respect to chamber 25 extends through only one quadrant of the cross-section of the chamber. This construction whicn results in the recircul'ating iiow enables the pump of FIG. 1 to have casing 20 with a substantially reduced outside diameter for a given flow condition. In addition to providing a recirculating flow within chamber 25, surface 37a of insert 37 directs the returning iiow against surface 30d of the impeller and due to the engagement of the flow with surface 30d, the fluid is accelerated. As a result of the recirculating flow of pump 29, the pump is capable of greater output at inc-reased efficiency as compared to a pump having a conventional centrifugal impeller arrangement with the conventional scroll casing.

A further advantage of the pump of FIG. 1 is that the central portion of the vortex is adapted to transport any air or gas entrained in the fluid being pumped, since the centrifugal accelerations in the vortex urge the denser liuids outwardly from the gas.

Pump 43 of FIG. 2 employs standardized pump casing 20 similarly as pum-p 29 of FIG. l. Rotary impeller 44 of pump 43 is a centrifugal type impeller having a plurality of divergent passage 44a. Impeller 44 is adapted to pump material suspended in a iluid such as a liquid as Well as liquids containing portionsof air or gas. In addition, impeller 44 is adapted to handle fluids having a substantially high viscosity.

When using impeller 44, it is not only possible to use standardized pump casing 20 but also to use insert 37 which is the same insert used in pump 29 of FIG. 1. Consequently pumps 29 and 43 which have distinctly different impellers can be constructed With the identical type of casing and insert. As a result the cost of ya new pump or the cost of spare parts can be reduced iu view of the interchangability.

Since impeller 44 only extends part way across chamber 25 within the housing, that is approximately one-quarter of the way -across the chamber, it is necessary to employ seal support 45 which is contoured to form cavity 46 between the support and impeller 44. Even though the surface of support 45 adjacent to the impeller is substantially different from that of the seal support 33, it is posible to machine the two supports from a comon casting and thereby make a single casting interchangeable with at least two pump designs.

Pumps 29 and 43 demonstrate the capabilities of standradially outward from t-he shaft. vided to establish a substantially circular cross-section for ardizing at least certain elements of pumps and still being able to provide a variety of different pumps. Thus in pumps 29 and 43 the identical casing 20 and insert 37 can be employed even though the pumps are equipped with distinctly different rotary impellers.

In FIG. 3 pump 47 again employs pump casing 20. In pump 47 impeller 48 is withdrawn from chamber 25 of the casing into `bore 22 of the casing. As a result, seal support 49 is of a reduced axial dimension as compared to seal support 33 :and 45. Surface 49a of the seal support is profiled to form cavities which cooperate with back blading 50 of the impeller in order to oppose a pressure build-up in the cavities which reflects the pressure within chamber 25. The operating characteristic Iand the nature of the ow in chamber 47 is disclosed in my United States Patent No. 3,171,357, issued Mar. 2, 1965 and entitled Pump In pump 47 it is desired to maintain a substantially open chamber 25 throughout its extent and including the region adjacent to inlet 28. For this reason it is unnecessary in pump 47 to use an insert of the type shown in pumps 29 and 43. In view of this, casing 26 can be employed by assembling into the pump after casting or after other forms of fabrication, but prior to the machining of recesses 38 and 42 which are shown in FIGS. 1 and 2. Thus the casting of casing having a curved surface as shown in FIG. 3 can be used.

In the alternative, where casing 20 has already been machined or otherwise worked to provide recess 38 and seat 42, the recess and seat can be filled or faired-in by fthe provision of inserts 51 and 52, respectively. Thus yit can be seen that pump 47, in addition to pumps 29 and 43, can be constructed with standardized pump casing 20.

VHere it should be noted that bore 22 of the casing, which merely receives the seal support in pumps 29 and 43, here Yserves as the stationary shroud for the impeller which contributes to the recirculation or the 'formation of a vortex adjacent to blades 48a of the impeller.

FIG. 4 shows a further pump 53 which utilizes standardized pump casing 20. In pump 53 impeller 54 is of the centrifugal-type having a combined axial and radial ow pattern. Thus, passages 54a of the impeller, while extending radially with respect to `shaft 55, `also extend Again insert 56 is prochamber by deflecting the flow inwardly toward outer surface 54b of -the impeller. The insert is adapted to t recess 38 and seat 42 of casing 20. Seal ring 57 attached to insert 56 forms a seal with respect to the outside diameter of the adjacent portion of impeller 54. In this way, leakage between the inlet and chamber 25 is prevented. Similarly, seal ring 58 mounted in seal support 59 seals chamber 25 from cavity 60 -at the rear portion of the impeller. Impeller 54 can be provided with openings or vents 54C which are similar to vents 30h of impeller in pump 29. Surface 59a of seal support A59 forms a portion of the wall of chamber 25 in casing 20. Consequently, surface 59a is profiled to substantially continue the radius of curvature passages 54a so that flow passes smoothly from impeller 54 to adjacent surface 59a. As in Ithe other pumps, a recirculating or vortex type flow is established in casing 20. In addition, flow passing from insert 56 to adjacent surface 54h of the impeller is accelerated by engagement with the impeller yand thereby the vortex action is increased.

In pump 61 of FIG. 5, again standardized casing 20 is employed. Here the rotary impeller includes propeller 62 mounted upon shaft 63 and retained in place by nut 64. In pump 61, contrary to the other pump arrangements, the insert to be mounted adjacent to the inlet opening fof the casing is integrated with the seal support in the form of support assembly 65. Thus, the support assembly includes seal support 65a, insert portion 65b and a plurality of divergent passages 65C which extend in an Aaxial and an outward radial direction from propeller 62.

Passages 65e are formed by guide blades extending there between which serve to direct the iiow from propeller 62 toward chamber 25. The passages blend into seal support 65a and subsequently to the inner surface of casing 20.

Again insert portion 65b is adapted to engage recess 38 and seat 42 of casing 20. As a result, pump 6.1 comprises another embodiment which can be built about the standardized pump casing 20 of the invention. L A further advantage of pump 61 is that propeller 62 can serve to produce a mixing action of yany material suspended in the fluid being delivered to inlet 28. In addition, due to the propeller characteristic, pump 61 can be employed where there is a desire to handle a comparatively large fiow at a reduced head. Where any portion of support assembly 65 is subjected to relatively rapid wear, the support assembly can be formed from a plurality of separate support elements so that elements experiencing Wear can be replaced without the need of replacing the entire assembly.

The standardized casing of the invention and its insert member not only simplify the pump construction problems of a pump manufacturer and reduce the number of different components which he must manufacture and also keep in inventory, but it also directly benefits the purchaser of the pump. After having bought one or more pumps with a given type of impeller, the purchaser may find that he no longer can use the particular impeller to advantage, In such a case the purchaser can safeguard the major portion of his pump investment by converting to the types of impeller which meets his new needs. In converting, the purchaser may merely have to change impellers. In other cases a new insert or seal support may be required with the new impeller. In any event however, the purchaser is able to continue to use at least the casing and the driving equipment of the original pump.

what is claimed:

1. A pump casing assembly adapted for receiving a rotary impeller mounted upon a shaft, the rotary impeller being any one type of rotary impeller selected from a plurality of different types of rotary impellers, each of the plurality of types of rotary impellers having a pump casing cover and means for sealing said shaft with respect thereto, said pump casing assembly comprising a standardized pump casing having a pair of wall portions disposed opposite and spaced apart from one another and an annular wall portion connecting together said pair of Wall portions, said annular Iwall portion having an outlet opening for said casing, one of said pair of wall portions having Ian additional opening disposed therein for -receiving the impeller and shaft, said one wall portion adjacent said additional opening being adapted to engage the pump casing cover when the impeller is disposed within said casing, the other of said pair of wall portions h-aving an inlet opening; and an insert member disposed adjacent to said opening and being exposed to the interior of said casing, said insert member being any one form of a plurality of different forms Iof insert members each of the plurality of insert members having a cylindrical opening for directing the flow of uid moving through said inlet opening toward the impeller and certain of the plurality of insert members additionally having means for guiding the fluid for recirculation within the casing, whereby said standardized pump casing can be selectively -assembled 'with any one type of the plurality of types of rotary impellers.

2. A pump casing assembly in accordance with claim 1 in which said insert member has a central opening in line with said inlet opening and a circumferential surface extending about the central axis of said casing, said surface being at a varying radial distance lfrom said central axis, which is maximum adjacent to the other of said pair of wall portions and minimum opposite thereto.

3. A pump casing assembly in accordance with claim 2 in which a cross-section of the circumferential surface of said insert member taken along a plane which includes the central axis of the casing corresponds substantially to a portion of a circle, whereby said insert member converts the interior of the casing substantially into a toroidal form.

4. A pump casing assembly in accordance with claim 1 in which said insert member includes means for sealing said cylindrical opening thereof with respect to the impeller, whereby the incoming flow is directed to the impeller.

5. A pump casing assembly in accordance with claim 4 in which said means for sealing said cylindrical opening of said insert member with respect to the impeller comprises a sealing ring mounted on said insert member and yadopted substantially to engage the impeller.

6. A pump comprising a shaft, a rotary impeller mounted upon said shaft and being any one type of rotary impeller selected from a plurality of different types of rotary impellers, a pump casing including .a pair of wall portions disposed and spaced apart from one another and an annular Wall portion connecting together said pair of wall portions to form a chamber, said annular wall portion having an outlet opening for said chamber, one of said pair of wall portions having an additional opening disposed therein for receiving the impeller into said chamber, said impeller being disposed within said chamber and offset toward said one wall, said impeller extending from adjacent the plane of said one wall portion toward the interior of said chamber, the flow from said impeller being directed radially outwardly along said one wall portion toward said annular wall portion, a pump casing cover having a passage therein through which said shaft extends, said one wall portion adjacent said additional opening being `adapted to engage said pump casing cover when the impeller is disposed within said casing, the other of said pair of wall portions having an inlet opening, an insert member which is any one of a plurality of different forms of insert members, each of the plurality of insert members having a cylindrical opening for directing the ow of fluid moving through said inlet opening toward the impeller and certain of the plurality of insert members additionally having means for guiding the uid for recirculation within the casing, and means adjacent said inlet opening and exposed to the interior of said casing for engaging said insert member, whereby said standardized pump casing can be selectively assembled with any one type of plurality of types of said impellers.

7. A pump in accordance with claim 6 in which said impeller comprises structure forming a plurality of radially extending tubular passages curving from the central axis lof the pump in an outward radially extending direction, the peripheral openings of said passages being disposed within said chamber and adjacent to said one wall portion, whereby the flow from said impeller passes adjacent to said one wall portion and toward said annular wall portion for establishing recirculation in the chamber of said casing.

8. A pump in accordance with claim 7 in which the tubular passages of said impeller have a diverging transverse cross-section taken in a plane passing through the length ofthe central axis of said pump.

9. A pump in accordance with claim 6 in which said passages of said impeller extend axially and radially outwardly from adjacent said inlet opening to adjacent said one wall portion, the flow from the periphery of said irnpeller being directed within the chamber along the surface ot said one wall portion toward said annular wall portion, whereby recirculation within the chamber is maintained.

10. A pump in accordance with claim 9 in which said passages of said impeller converge from adajcent said inlet opening toward the peripheral portion of said impeller.

11. A pump in accordance with claim 6 in which said impeller comprises structure forming a plurality of curved tubular passages extending from adjacent the central axis of the impeller toward the periphery thereof, the peripheral openings of said passages being disposed inwardly from said wall portion toward the interior ofthe chamber and in which said insert member comprises a body having a central opening for connection to said inlet opening and an external outer surface converging from adjacent said other wall portion toward said impeller, whereby the flow of iiuid from adjacent said other wall portion is directed toward said impeller.

12. A pump in accordance with claim 11 in which means are provided for sealing said insert member with respect to said impeller.

13. A pump comprising a shaft, a propeller-type impeller mounted upon said shaft, a pump casing including a pair of wall portions disposed and spaced apart from one another and an annular wall portion connecting together said pair of wall portions to form a chamber, said annular wall portion having an outlet opening for said chamber, one of said pair of wall portions having an additional opening disposed therein for receiving the impeller into said chamber, said one wall portion adjacent said additional opening being adapted to engage said pump casing cover when the impeller is disposed within said casing, the other of said pair of wall portions having an inlet opening, said impeller being -disposed adjacent to said inlet opening, and means disposed Within said chamber for directing the flow from said impeller in an outward radial direction toward said one Wall portion, whereby the flow is directed for recirculation within said chamber.

14. A pump in accordance with claim 13 in which said means for directing the flow from said impeller in an outward radial direction toward said one wall portion comprises a center body having a plurality of passages curvin-g radially outwardly from adjacent said propeller-type impeller for directing the flow therefrom to adjacent said one wall portion.

15. A pump in accordance with claim 14 in which said center body includes a flange extending toward the interior of said chamber from said other wall portion and flaring outwardly with respect to the central axis of said charnber, said ilange directing flow adjacent said other wall portion to recirculate within said chamber.

16. A standardized one piece pump casing adapted for receiving a rotary impeller mounted upon a shaft, the rotary impeller being any one type of rotary impeller selected from a plurality of different types of rotary impellers, each of the plurality of different types of rotary impellers having a different one of a plurality of pump casing covers with means therein for supporting the impeller shaft with respect to the pump casing cover and a dilferent one of a plurality of insert members corresponding to the different impellers, said one piece pump casing having a central axis and comprising a wall portion extending radially with respect to the central axis of said one piece casing which is substantially coincidental with the axis of rotation of an impeller, an annular wall portion extending from about the periphery of said wall portion and having a curved inner surface facing toward the central -axis of said casing, said curved inner surface being substantially semi-circular in section when taken along any plane which includes the central axis of said casing, said annular wall portion having an outlet opening for said casing, an additional wall portion extending from said annular wall portion and away from said wall portion, said additional wall portion having a cylindrical bore with its axis coincidental with the central axis of said casing, said bore being :substantially aligned with the diameter of the semi-circular section of said annular wall portion, said cylindrical bore being adapted to receive at least a portion of the pump casing cover when an impeller is disposed in said one piece casing to enable the inner surface of the pump casing cover to cooperate with said wall portion and said annular wall portion in forming a cavity in communication with said impeller, said wall portion having an inlet opening and means adjacent said inlet opening andV exposed to the interior of said casing for engaging at least one of-the plurality of different insert members, each of the plurality of dilerent insert members having a cylindrical opening for directing the flow of fluid moving through said inlet opening toward said impeller and certain of the plurality of insert members additionally having means for guiding the uid for recirculation Within the casing, whereby said standardized pump casing can be selectively assembled with any one type of the plurality of types of rotary impellers.

17. A standardized pump casing in accordance with claim 16 in which said means adjacent said inlet -opening and exposed to the interior of said casing for engaging at least one insert member comprises at least one recess in said other wall.

18. A standardized pump casing in accordance with claim 16 in which said means adjacent said inlet opening and exposed to the interior of said casing for engaging at least one insert member comprises a counterbored opening disposed about said inlet opening and extending outwardly from the interior of said casing along the central axis thereof.

19. A standardized pump casing in accordance with claim 16 in which said means adjacent said inlet opening and exposed to the interior of said casing for engaging at least one insert member comprises a seat formed by a relieved portion of said other Wall portion, said relieved portion extending in a radial outward direction Yfrom said inlet opening.

20. A pump assembly adapted for the construction of a plurality of various pump types comprising a standardized one piece pump casing including a substantially radial Wall portion having an inlet opening, an `annular wall portion extending from about the periphery of said radial Wall portion, said annular Wall portion having an outlet opening, said radial wall portion and said annular wall portion forming a chamber Within the Casin-g, and a substantially cylindrical portion extending from said annular Wall portion opposite and away from said radial Wall portion, said cylindrical portion having a cylindrical bore disposed opposite said inlet opening; one of a plurality of impellers of Various types being disposed in said casing; one of a plurality of dilerent inserts of various types each associated with a different one of said plurality of impellers being disposed in said casing about said inlet opening and facing said chamber; one of a plurality of different support members each associated with va dierent one of said plurality of impellers being disposed in said cylindrical bore; each of said inserts, said impellers and said support members being adapted to be inserted through said cylindrical bore with said support member closing said cylindrical bore with respect to said chamber.

21. A pump assembly in accordance with claim 16 in which each of said inserts have a curved outer surface adapted to form an annular chamber of substantially circular cross section together with said annual wall portion of the casing.

References Cited by the Examiner UNITED STATES PATENTS 765,969 7/1904 Hanson 103-103 1,029,979 6/ 1912 Ehrhart 103-114 1,991,761 2/1935 McHugh 103-103 2,469,125 5/ 1949 Meisser 10388 2,743,120 4/ 1956 Haentjens et al 103-111 2,992,617 7/ 1961 Kroeger 103-103 3,146,722 9/1964 Warrnan 103-114 FOREIGN PATENTS 110,760 6/ 1940 Australia.

578,473 6/ 1959 Canada.

388,267 5/1908 France.

1,082,123 5/1960 Germany.

8,020 6/ 1890 Great Britain. 27,740 12/1912 Great Britain. 285,335 2/ 1928 Great Britain. 269,595 11/ 1950 Switzerland.

DONLEY I. STOCKING, Primary Examiner. HENRY F. RADUAZO, Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTIGN Patent N0. 3,316,848 May Z, 1967 Emile Egger It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent Should read as corrected below.

Column l, line 20, for "viscosty" read viscosity line 23, for "gasses" read gases column 2, line 20, for "winch" read which line 22, for "It is a further object of the invention to provide standardized read It is also an object of the invention to provide a standardized line 46, for "additon" read addition same line 46, for "cylndrical" read cylindrical line 59, for "inlet and" read inlet opening and column 3, line 24, for "openings" read opening column 4, line 8, for "portion" read portions line 13, for "inconjunction" read in conjunction line 18, for "has substan" read has a substanlines 2l and 5l, for "passage", each occurrence, read passages line 7l, for "of the seal" read of seal column 5, line 10, for "support" read supports column l0, line 1S, for "annual" read annular Signed and sealed this 21st day of November 1967.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. EDWARD J. BRENNER Attesting Officer Commissioner of Patents 

1. A PUMP CASING ASSEMBLY ADAPTED FOR RECEIVING A ROTARY IMPELLER MOUNTED UPON A SHAFT, THE ROTARY IMPELLER BEING ANY ONE TYPE OF ROTARY IMPELLER SELECTED FROM A PLURALITY OF DIFFERENT TYPES OF ROTARY IMPELLERS, EACH OF THE PLURALITY OF TYPES OF ROTARY IMPELLERS HAVING A PUMP CASING COVER AND MEANS FOR SEALING SAID SHAFT WITH RESPECT THERETO, SAID PUMP CASING ASSEMBLY COMPRISING A STANDARDIZED PUMP CASING HAVING A PAIR OF WALL PORTIONS DISPOSED OPPOSITE AND SPACED APART FROM ONE ANOTHER AND AN ANNULAR WALL PORTION CONNECTING TOGETHER SAID PAIR OF WALL PORTIONS, SAID ANNULAR WALL PORTION HAVING AN OUTLET OPENING FOR SAID CASING, ONE OF SAID PAIR OF WALL PORTIONS HAVING AN ADDITIONAL OPENING DISPOSED THEREIN FOR RECEIVING THE IMPELLER AND SHAFT, SAID ONE WALL PORTION ADJACENT SAID ADDITIONAL OPENING BEING ADAPTED TO ENGAGE THE PUMP CASING COVER WHEN THE IMPELLER IS DISPOSED WITHIN SAID CASING, THE OTHER OF SAID PAIR OF WALL PORTIONS HAVING AN INLET OPENING; AND AN INSERT MEMBER DISPOSED ADJACENT TO SAID OPENING AND BEING EXPOSED TO THE INTERIOR OF SAID CASING, SAID INSERT MEMBER BEING ANY ONE FORM OF A PLURALITY OF DIFFERENT FORMS OF INSERT MEMBERS EACH OF THE PLURALITY OF INSERT MEMBERS HAVING A CYLINDRICAL OPENING FOR DIRECTING THE FLOW OF FLUID MOVING THROUGH SAID INLET OPENING TOWARD THE IMPELLER AND CERTAIN OF THE PLURALITY OF INSERT MEMBERS ADDITIONALLY HAVING MEANS FOR GUIDING THE FLUID FOR RECIRCULATION WITHIN THE CASING, WHEREBY SAID STANDARDIZED PUMP CASING CAN BE SELECTIVELY ASSEMBLED WITH ANY ONE TYPE OF THE PLURALITY OF TYPES OF ROTARY IMPELLERS. 